To be fair in price comparison, this is used and one generation back. "Used, quality"... is the way to go for buying a computer IMV.
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=5993475&CatId=11704 Maybe not. Dell workstation $193
I buy smart phones like that, Qualcomm 4 or 6 series chipset instead of series 8 badged Nokia 6 or 7.1 android one. $200 to $300.
Installed OS is not a marker. Look at launch date for both the CPUs: https://ark.intel.com/products/83359/Intel-Xeon-Processor-E5-2640-v3-20M-Cache-2-60-GHz- https://ark.intel.com/products/28032/Intel-Xeon-Processor-E5345-8M-Cache-2-33-GHz-1333-MHz-FSB- On top of that the first is 8 cores with 16 threads; the latter is 4 cores. You get what you pay.
Here's a review from 2006 http://www.cadalyst.com/hardware/first-look-review-dell-precision-490-workstation-5828